(1) Field of the Invention
The present invention relates to the technical field of recording of audiovisual contents (hereafter “AV contents.”)
(2) Description of the Related Art
An AV content is defined by a combination of an audiovisual stream (hereafter “AV stream”) and playback control information such as PlayList information. Generally, large-capacity removable mediums are used for recording AV contents. The storage capacity of a recent removable medium is increasing and it is said that a single layer Blu-ray disc will soon be able to store up to 25 GB and an 8-layer Blu-ray disc capable of storing up to 200 GB will soon be put into practical use. It is also expected that semiconductor memory cards having solid copyright protection function and being capable of storing multi-terabyte data may become available within five years.
Meanwhile, the advancement of coding technology is improving compression efficiency year-by-year, so that a two-hour movie may be encoded with MPEG-4 AVC with the bit rate of 8 Mbps or so to provide a sufficiently Hi-vision content. In this case, the data size of such a two-hour Hi-vision content is about 2×60×60×8 Mbits=7.2 GB. Which is to say, a single-layer 25 GB removable medium is capable of storing up to three two-hour Hi-vision contents. Similarly, a dual-layer 50 GB Blu-ray disc is capable of storing up to twelve Hi-vision contents each of which is one-hour long (i.e. twelve episodes corresponding to one television season).
Note that the techniques of recording AV contents each defined by an AV stream and PlayList information known in the art include the one disclosed in the following patent document.
Patent Document 1:
JP Patent Application Publication No. 9-282848 (JP Patent Application No. 8-83478)